(1) Field of the Invention
The present invention relates to an optical connection (wiring) switching apparatus and a management control unit thereof, for example, an optical connection switching apparatus and a management control unit thereof suitable for the connection management in in-datacenter or in-company optical network or the like.
(2) Description of the Related Art
Along with the recent speeding-up of transmission signals and wide-spreading of networks, an optical signal network is being constructed which employs, as a transmission medium, an optical fiber having a large-bandwidth property and a low-loss property. Although the high-speed signal and the broadband transmission has been peculiar to the communications in the backbone networks so far, because of the appearance of various types of Ethernets (registered trademark), such as the Giga-bit Ethernet (GbE) and 10-Giga-bit Ethernet (10 GbE), and a fiber channel (FC), the speeding-up of transmission signals and the wide-spreading of the networks are advancing even in Ethernets such as LAN (Local Area Network) and other networks.
Along with this situation, the construction of an optical network is advancing even in a LAN using an Ethernet, a SAN (Storage Area Network) using a fiber channel and others. In such an optical network, various types of information apparatus (IT equipment) such as personal computers and a layer-2/layer-3 electric switch are connected to each other through the use of an optical fiber on a one-to-one basis, and at the construction or change of a network, there is a need to employ a facility capable of switching the optical signal path when a trouble (disorder) occurs.
For example, as the network in which these LAN and SAN exist in a state mixed, there is an in-datacenter network. In general, the optical connection in the datacenter is under management through the use of a control panel, in which optical adapters are arranged, called a patch panel and, for example, the optical path switching is realized by manually inserting/drawing fiber connectors, and the connection management is made through the tag attachment to both the ends of a fiber and the connection state recording made by the manual inputting.
Thus, as an enterprise network such as an in-datacenter network, a network has been constructed through the use of a Giga-bit Ethernet, 10-Giga-bit Ethernet, fiber channel (FC) or the like, and the transmission rate of this network has been as high as 1.0 Gbps, 10 Gbps or more and, as represented by a service such as a wide-area Ethernet, the transmission distance has been lengthened. For this reason, as the transmission medium, there has been employed an optical fiber superior in large-bandwidth property and low-loss property.
So far, the connection between IT (Information Technology) equipment and layer-2/layer-3 electric switch has been made on a one-to-one basis and, hence, there is a need to install a large number of optical fibers. Moreover, the connection management for these optical fibers has been made in the present situation. In general, the construction and change of a network system or the change of the connection of optical fibers stemming from the occurrence of a trouble lead to complicated operations such as optical fiber connection device confirmation tagging, connection diagram renewal and connection confirmation.
Such a network environment management method creates a problem in that there is a need to take a large number of processes. Moreover, inmost cases, the actual wiring operations and the network construction operations are conducted in a separate fashion and there is a need to share the information on connection devices even in remote sites.
In addition, since the signals flowing an optical fiber range widely in type, such as various Ethernets (Ethernet, Fast Ethernet, Giga-bit Ethernet, 10-Giga-bit Ethernet) and fiber channels, mainframe interfaces (OCLINK, ESCON/FICON), for the connection of equipment having these interfaces (protocol and bit rate) through an electric switch, the number of electric switches (Ethernet switch, fiber channel switch, and others) is required to be equal to the number of types of interfaces, which leads to an extremely high cost.
For this reason, as the route switching apparatus handling high-speed signals in the Giga-bit Ethernet, the fiber channel or the like, a hopeful view is taken on an optical connection switching apparatus. This optical switch was originally developed for use in a transmission apparatus of a trunk network (backbone network) and, since the route switching can be made in a state of optical signal, the optical switch does not suffer from the delay occurring in an electric switch. Moreover, since there is no need to convert an optical signal into an electric signal, it also has a transparency in that it is possible to make the route switching on arbitrary protocols and arbitrary bit-rate signal.
In this connection, as a conventional technique on the fiber channel, there are techniques proposed, for example, in Japanese Patent Laid-open Nos. HEI 10-135952 and HEI 11-65980. The technique of Japanese Patent Laid-open No. HEI 10-135952 is for providing a fiber channel exchange which mutually connects a plurality of equipment to each other through node ports (N ports) related thereto, and the technique of Japanese Patent Laid-open No. HEI 11-65980 is for, in the connection configuration using fabrics in a fiber channel interface, speeding up the response of the fabrics.
In addition, as the conventional network interface apparatus, there are the techniques proposed in Japanese Patent Laid-Open Nos. 2000-341359 and 2000-209622. The technique of Japanese Patent Laid-Open No. 2000-341359 is for providing an apparatus capable of making the re-construction of ports in a communication network efficiently at a low cost, and includes a plurality of optical ports and a plurality of electronic circuits and an electronic switch disposed between the plurality of optical ports and the plurality of electronic circuits to re-construct the connection between one selected from the plurality of optical ports and one of the electronic circuits. The technique of Japanese Patent Laid-Open No. 2000-209622 relates to a serial transmission switching system capable of coping flexibly with the addition or change of the existing transmission-rate communication equipment and the addition of new transmission-rate communication equipment.
Still additionally, as the conventional techniques related to the fiber channel and the Giga-bit Ethernet, there is a technique proposed in Japanese Patent Laid-Open No. 2002-232409. This technique relates to a pattern detecting method and apparatus for monitoring a data stream in the fiber channel, Giga-bit Ethernet and others. That is, to most interfaces, as in the case of the fast fiber channel and Giga-bit Ethernet interface, it is useful to produce a special data stream with attention being paid to a given jitter in the interface and/or the equipment or other similar deterioration characteristics. Therefore, such a test apparatus is operated at a specified time of the data stream.
Meanwhile, for incorporating these network apparatus into a system, a redundant configuration is employed in most cases. In the case of routers acting as a network apparatus, information are interchanged between the routers in order to grasp states. Companies have presented diverse protocols for placing the routers into a redundant condition by interchanging the information.
For example, Cisco Systems Co., Ltd. has prepared HSRP (Hot Standby Routing Protocol) as the protocol for making the router redundant. That is, in a state where one IP (Internet Protocol) address is allocated to each router, one IP address is further allocated to all the routers multiplexed and, for making communications, a request is transmitted to the IP address for all the routers. The router to be used for common communication is one in number and, when the router which is in use comes to a stop, the other one router automatically makes communications in place of the router which has come to a stop. The time needed for the switching therefor is approximately one second.
In addition, although there is no interoperability (interchangeability), as a similar technique, there has been known VRRP (Virtual Router Redundancy protocol). A plurality of routers matching with the VRRP are grouped into one group and, usually, one of the routers takes care of communications, and when this router falls into a trouble, a router belonging to the same group automatically takes over the communications. Although the router which makes communications is limited to one in the same group, since one router can belong to a plurality of groups, it is also possible to realize the load distribution simultaneously according setting.
The foregoing techniques relate to a technique in which a routing table which is information on the layer 3 is interchanged among a plurality of routers and, when a router falls into a trouble, a path is set so as to bypass the router which has fallen into the trouble, thereby securing a communication route.
Moreover, as redundant arrangements of an optical switch, there are techniques proposed in Japanese patent Laid-Open Nos. 2002-95023 and 2003-289557, and others. In these techniques, power is monitored in each port of an optical switch set as a work system and, at the time of the detection of a power disconnection, switching is made to a port of an optical switch set as a spare (protection) system. In the arrangement, in addition to N×N optical switches which are a main switch, switches for the selection of the work system and the spare system are connected vertically, and a port relationship for placing an arrangement into a redundant condition is uniquely determined because of the physical connections. Still moreover, in the technique proposed in Japanese patent Laid-Open Nos. 2004-40726, when a trouble is detected on the work link side in a redundant input/output link of an optical switch, switching is made with reference to a protection table (port information) which specifies a portion to be restored at the detection of the trouble.
For the management of the optical connections (wiring) in a optical network such as an optical LAN (Local Area Network) constructed using an optical connection switching apparatus (optical switch) in a datacenter or in an enterprise, there is a need to capture what type (for example, protocol or bit rate) of equipment is connected to each port of the optical connection switching apparatus (information about the equipment). Although this requires monitoring the contents of an optical signal, it is impossible, for that the existing optical connection switching apparatus is not designed to analyze the contents of an optical signal while conducting the route switching in a state of the optical signal. This also applies to the aforesaid Japanese Patent Laid-Open Nos. HEI 10-135952, 2000-341359, HEI 11-65980, 2000-209622 and 2002-232409, and these documents does not disclose nor teach a technique of capturing which of ports of an optical switch is connected to what type of equipment for the connection management.
Furthermore, in the case of the employment of the above-mentioned optical connection switching apparatus, in a datacenter network, there is a need to construct a system for looking toward the nonstop for 365 days and 24 hours. For this reason, there is a need to enhance the reliability of the system by making this apparatus and power supply redundantly. The redundant optical connection switching apparatus requires a link redundancy for the switching to a spare link when a trouble occurs in a work link and requires a node redundancy for the switching to a spare apparatus (a plurality of collected ports) when a trouble occurs in a work apparatus.
Since the above-mentioned optical connection switching apparatus is designed to acquire the information on the apparatus having an optical communication interface to be connected optically for managing the connection between the apparatuses, in the work and spare systems, the same apparatus is not connected to the port with the same number, but the number of a port to be connected is optionally determined. Therefore, in the case of the conventional switching to a spare apparatus at the occurrence of a trouble, since the frequency of change of the apparatus to be connected is high, there is a high possibility that only the link switching cannot achieve the normal connection. Moreover, since the control in the physical layer is principally conduced instead of the control in the layer 3 such as a routing table, a redundancy protocol for a router cannot cope with it and, hence, a new switching procedure becomes necessary. Still moreover, in the case of the employment of a protection table (port information), an increase in the number of ports causes a complicated management and then leads to a low reliability.